Java高级语法笔记-自定义异常类

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package my;

public class BadFormatException extends Exception
{
	String reason;
	public BadFormatException(String reason) {
		this.reason=reason;
	}
	@Override
	public String getMessage()
	{
		return "格式错误（"+reason+")";
	}
}

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package my;

public class BadRangeException extends Exception
{
	String reason;
	public BadRangeException(String reason) {
		this.reason=reason;
	}
	@Override
	public String getMessage()
	{
		return "范围错误（"+reason+"）";
	}
	
}

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package my;

public class Date
{
	public int year,month,day;
	public void parse(String dateStr) throws IllegalCharException,BadFormatException,BadRangeException
	{
		//检测非法字符
		for(int i=0;i<dateStr.length();i++) {
			char ch=dateStr.charAt(i);
			if(ch>='0'&&ch<='9') ;
			else if(ch=='-');
			else throw new IllegalCharException(i);
		}
		//检测分割符
		int  p1=dateStr.indexOf("-");
		if(p1<0)	throw new BadFormatException("找不到第1个横杠！");
		int p2=dateStr.indexOf("-",p1+1);
		if(p2<0)	throw new BadFormatException("找不到第2个横杠！");
		
		//检测年月日的长度
		String s1=dateStr.substring(0, p1);
		String s2=dateStr.substring(p1+1, p2);
		String s3=dateStr.substring(p2+1);
		if(s1.length()!=4)	throw new BadFormatException("格式不对：年份错误！");
		if(s2.length()!=1&&s2.length()!=2)	throw new BadFormatException("格式不对：月份错误！");
		if(s3.length()!=1&&s3.length()!=2)	throw new BadFormatException("格式不对：日份错误！");
		
		this.year=Integer.valueOf(s1);
		this.month=Integer.valueOf(s2);
		this.day=Integer.valueOf(s3);
		
		//有效性检测
		if(month<0||month>12) throw new BadRangeException("数据无效：月份不能为"+month);
		if(day<0||day>31)	throw new BadRangeException("数据无效：日期不能为"+day);
		
	}
	@Override
	public String toString()
	{
		return year+"年"+month+"月"+day+"日";
	}
}

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package my;


public class HelloWorld
{
	public static void main(String[] args)
	{		
		Date d=new Date();
		try {
			d.parse("2016B-12-1");
			System.out.println("日期为："+d.toString());
		}catch(IllegalCharException e) {
			System.out.println(e.getMessage());
		}
		catch(BadFormatException e) {
			System.out.println(e.getMessage());
		}
		catch(BadRangeException e) {
			System.out.println(e.getMessage());
		}
		catch(Exception e) {
			
		}
	} 

}

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package my;

public class IllegalCharException extends Exception
{
	int position=0;
	public IllegalCharException(int pos) {
		this.position=pos;
	}
	@Override
	public String getMessage()
	{
		return "非法字符（"+position+"）";
	}
	public int getPosition() {
		return position;
	}
}